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相关论文: Ly-alpha Radiative Transfer: A Stokes Vector Appro…

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We present a simple but powerful technique for the analysis of polarized emission from radio galaxies and other objects. It is based on the fact that images of Stokes parameters often contain considerably more information than is available…

星系天体物理 · 物理学 2021-11-10 Lawrence Rudnick , Debora Katz , Lerato Sebokolodi

Polarization speckle is a fine granular light pattern having spatially varying random polarization profile. We generate these speckle patterns by using the scattering of Poincar\'e beams, a special class of vector vortex beams, through a…

光学 · 物理学 2017-05-15 Salla Gangi Reddy , Vijay Kumar , Yoko Miyamoto , R. P. Singh

Ly$\alpha$ emission is key to understanding the process of cosmic reionisation. JWST is finally enabling us to measure Ly$\alpha$ emission deep into the epoch of reionisation for an increasing number of galaxies. However, discrepancies…

星系天体物理 · 物理学 2024-08-30 Aniket Bhagwat , Lorenzo Napolitano , Laura Pentericci , Benedetta Ciardi , Tiago Costa

We present a new model for the observed Lyman alpha blobs (LABs) within the context of the standard cold dark matter model. In this model, LABs are the most massive halos with the strongest clustering (proto-clusters) undergoing extreme…

宇宙学与河外天体物理 · 物理学 2015-06-11 Renyue Cen , Zheng Zheng

The Lya line transfer in an extremely thick medium of neutral hydrogen is investigated by adopting an accelerating scheme in our Monte Carlo code to skip a large number of core or resonant scatterings. This scheme reduces computing time…

天体物理学 · 物理学 2009-11-07 Sang-Hyeon Ahn , Hee-Won Lee , Hyung Mok Lee

We study the clustering properties of z~5.7 Lyman-alpha emitters (LAEs) in a cosmological reionization simulation with a full Lya radiative transfer calculation. Lya radiative transfer substantially modifies the intrinsic Lya emission…

宇宙学与河外天体物理 · 物理学 2015-05-18 Zheng Zheng , Renyue Cen , Hy Trac , Jordi Miralda-Escude

We investigate Lyman-alpha (Ly$\alpha$) transmission spikes at $5.2 < z < 6.8$ using synthetic quasar spectra from the ``Cosmic Reionization On Computers" simulations. We focus on understanding the relationship between these spikes and the…

宇宙学与河外天体物理 · 物理学 2025-07-01 Hanjue Zhu , Nickolay Gnedin , Camille Avestruz

An approach for measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics is described. A set of multilayer-coated flats reflect the dispersed X-rays to the instrument detectors. The intensity variation…

天体物理学 · 物理学 2009-11-13 Herman L. Marshall

Long Period Transients (LPTs) are a recently identified class of sources characterized by periodic radio bursts lasting seconds to minutes, with flux densities that might reach several tens of Jy. These radio bursts repeat with periodicity…

高能天体物理现象 · 物理学 2026-02-11 Nanda Rea , Natasha Hurley-Walker , Manisha Caleb

Stacking polarized radio emission in SKA surveys provides statistical information on large samples that is not accessible otherwise due to limitations in sensitivity, source statistics in small fields, and averaging over frequency…

天体物理仪器与方法 · 物理学 2015-01-05 J. M. Stil , B. W. Keller

Recent work has shown that UV-luminous reionization-era galaxies often exhibit strong Lyman-alpha emission despite being situated at redshifts where the IGM is thought to be substantially neutral. It has been argued that this enhanced…

We present an analysis of HI Lyman-alpha emission in deep VLT/MUSE observations of two highly magnified and extended galaxies at z=3.5 and 4.03, including a newly discovered, almost complete Einstein ring. While these Lyman-alpha haloes are…

Lyman-$\alpha$ photons enable the cosmic dawn 21-cm signal through a process called the Wouthuysen-Field effect. An accurate model of the signal in this epoch hinges on the accuracy of the computation of the Ly$\alpha$ coupling, which…

宇宙学与河外天体物理 · 物理学 2024-11-18 Shikhar Mittal , Girish Kulkarni , Thibault Garel

We perform Lyman-$\alpha$ (Ly$\alpha$) Monte-Carlo radiative transfer calculations on a suite of $2500$ models of multiphase, outflowing media, which are characterized by $14$ parameters. We focus on the Ly$\alpha$ spectra emerging from…

星系天体物理 · 物理学 2016-07-20 Max Gronke , Mark Dijkstra

BL Lac objects are active nuclei, hosted in massive elliptical galaxies, the emission of which is dominated by a relativistic jet closely aligned with the line of sight. This implies the existence of a parent population of sources with a…

高能天体物理现象 · 物理学 2016-11-26 Renato Falomo , Elena Pian , Aldo Treves

Existing ubiquitously in the Universe with the highest luminosity, the Lyman-$\alpha$ emission line encodes abundant physical information about the gaseous medium it interacts with. Nevertheless, the resonant nature of Ly$\alpha$…

星系天体物理 · 物理学 2022-05-11 Zhihui Li , Max Gronke

Lyman-$\alpha$ (Ly$\alpha$) emitting galaxies are powerful tools to probe the late stages of cosmic reionization. The observed sudden drop in Ly$\alpha$ fraction at $z>6$ is often interpreted as a sign of reionization, since the…

宇宙学与河外天体物理 · 物理学 2021-03-03 Sultan Hassan , Max Gronke

The process of the elastic scattering of photons on atoms, known as the Rayleigh scattering, is investigated. Expressing the scattering observables in terms of the electric and magnetic complex scattering amplitudes, we work over the…

原子物理 · 物理学 2020-10-20 A. V. Volotka , A. Surzhykov , S. Fritzsche

We present new results on the Ly-alpha emission-line kinematics of 18 z~2-3 star-forming galaxies with multiple-peaked Ly-alpha profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have…

宇宙学与河外天体物理 · 物理学 2015-05-28 Kristin R. Kulas , Alice E. Shapley , Juna A. Kollmeier , Zheng Zheng , Charles C. Steidel , Kevin N. Hainline

Polarimetric measurements, especially if extended at high energy, are expected to provide important insights into the mechanisms underlying the acceleration of relativistic particles in jets. In a previous work we have shown that the…

高能天体物理现象 · 物理学 2020-09-09 F. Tavecchio , M. Landoni , L. Sironi , P. Coppi